wooden ice boat mast

[DoyleH]

I have an ice boat that originally used a windsurfer rig. My mast exploded (very exiting) last year. The windsurfer rig was a pain in the ___ anyway, so I am in the process of building a wooden mast. I found some simple plans for a wooden mast on the Glen L website.

My question. Would adding 6 oz cloth and epoxy strengthen the mast? Would it make it too stiff? I have done some reading on DN ice boats and they talk about mast flex as a good thing.

I am currently building my 3rd kayak, so I have plenty of fiberglass cloth and epoxy on hand.

Where is the greatest load on the mast? near the boom, at the hounds? Should I just use epoxy/fabric at the high load areas?

Thanks for any input

[Tim B]

The DN plans include instructions for makeing a wood mast. These instructions include putting a layer of cloth and epoxy on the mast. Considering the amount of bend expected, it makes me wonder if this is wise. I'm sure it stiffens the mast for the first few bends, but after a few good runs I would think that there would be alot of cracks in the epoxy. All the DN's I've seen either have an aluminum mast or they are older wood ones built before cloth and epoxy were used.

[notwoodbut...]

Don't know much about DN masts but my friend builds masts and other DN parts. Found this deflection schedule on his website.
http://www.csi-composites.com/files/DEFLECTIONS.pdf
might be of interest.
I guess they do have some deflection!
http://www.csi-composites.com/images/photos/new% 20englands/032.jpg (http://www.csi-composites.com/images/photos/new%20englands/032.jpg)
sorry I don't know how to copy

[ 10-24-2005, 03:36 PM: Message edited by: notwoodbut... ]

[Todd Bradshaw]

This isn't the latest racing technology, but it's one source of instructions and there are still a fair number of boats out there using similar masts.
http://www.idniyra.org/articles/mast_made_easy.htm

If you want to read an explanation of the new, super-flexible models, there is a good basic one here:
http://www.nsibyc.com/science.asp

People spend years and years playing with iceboat mast flex and sailshape (sail cut needs to match the mast's bend characteristics to work well) and there aren't really any clear-cut answers which would apply to any mast or any sail. You can still have plenty of fun and go fast enough to scare yourself with something that has more traditional flex made from wood or aluminum (our touring two-place iceboat has a simple aluminum mast that's about 19'long with a diameter about like that of a Hobie 14). Mainsheet tensions are so high when you're running at speed that you will see a very noticable bend in almost any mast.

[Dan McCosh]

The DNs that use extreme bends use a carbon-fiber mast. The wood mast is in compression, and a skin of glass does little to increase the stength in this dimension. The old wood masts use a luff groove, which could be helped by the cloth, however. The loads on an iceboat mast, due to the lack of heeling moment, the high pressures generated at speed, and the high sheeting loads, are terrific. I have had a few destroyed by the compression loads. It is exciting. Making one that takes an extreme bend and lives is a bit of an art form. Ron Sherry, a member of our sail club, is the reigning DN world champion and makes his own masts.

[ 10-25-2005, 09:05 AM: Message edited by: Dan McCosh ]